In various crafts projects it is useful to be able to accurately cut elongated stock material, such as strips of wood, or the like, to length and at accurately reproducable angles. For example, in many construction projects it is desired to cut strips of wood so that the end cut is square, that is perpendicular to the longitudinal axis of the wood strip. At other times it is desirable to cut at angles other than 90.degree. such as at a 45.degree. angle to enable two such strips to be mitered to provide a square or right angle corner joint. Motorized miter saws, in which a power driven circular saw is pivotally supported on a support member for vertical swinging movement downwardly from a normal inoperative rest position towards a work support base structure while also pivotally supporting the saw support member on a vertical axis for angular swinging movement to preselected angular positions to effect a desired angle cutting of the work piece have been previously shown and saws of this type are disclosed, for example, in Niehaus et al U.S. Pat. No. 3,821,918 and are commonly referred to as chop saws. A disadvantage of such saws is the necessity for pivoting the saw assembly for angular setting and the weight and vibration of the saw necessitates that the saw support member be rather heavy and closely machined to provide for long life and continued accuracy. Among other disadvantages, this necessity makes such construction more expensive than might be otherwise desirable. Moreover, since the saw blade must descend to a position beneath the work supporting surface in order to completely sever the work piece, means must be provided to enable the saw to pass through the work supporting surface at a number of angular positions which further increases the complexity and, accordingly, the cost of such saws. In some saws this is achieved by providing a rotating platform which rotates with the saw, further adding to the complexity and expense of the machine. If such means are not provided, then a disposable work supporting surface, such as a piece of scrap wood, must be used beneath the work piece of a movable fence, or the like may be provided to enable relative lateral movement of the work piece and the saw path, therefore necessitating both the chopping movement of the saw and lateral movement of the work piece of saw which results in a loss of convenience and a possible lessening of accuracy as well as an increase in complexity and expense. In the present saw the difficulties are reduced by providing a pivotal fence for positioning the work piece and a fixed chordal clearance in the saw base for the saw blade together with novel and improved means for mounting the fence in position while guiding it for pivotal movement on the saw base.
Without getting into truly massive or welded structures for the work support base structure, the most economical base fabrication method to provide the requisite rigidity and strength is to cast the structure of metal. While such cast structures are basically inexpensive in comparison with a welded structure, a cast structure has the basic inconvenience that working surfaces need to be subsequently machined because the surface finish produced by processes such as sand casting are generally insufficient for work supporting surfaces and for bearing surfaces about which the miter fence pivots. Moreover, because of the limitation of the sand casting process and the contraction of metal during cooling following casting, actual dimensions are subject to substantially large tolerances which necessitate that critical surfaces and the structure defining pivotal axis be subsequently machined and each machining operation necessitated by the design generally increases the cost of the machine. The novel fence mounting of the present invention provides accurate positioning of the fence while yet minimizing the amount of machining necessary. By positioning the fence against a pair of machined steel pins pressed into the base and biasing the fence by spring means against the pins.